Happiness in the present moment consists of very different states from happiness about the past and about the future, and itself embraces two very distinct kinds of things: pleasures and gratifications. The pleasures are delights that have clear sensory and strong emotional components, what philosophers call "raw feels"; ecstasy, thrills, orgasm, delight, mirth, exuberance, and comfort. They are evanescent, and they involve little, if any, thinking. The gratifications are activities we very much like doing, but they are not necessarily accompanied by any raw feelings at all. Rather, the gratifications engage us fully, we become immersed and absorbed in them, and we lose self-consciousness. Enjoying a great conversation, rock climbing, reading a good book, dancing, and making a slam dunk are all examples of activities in which time stops for us, our skills match the challenge, and we are in touch with our strengths. The gratifications last longer than the pleasures, they involve quite a lot of thinking and interpretation, they do not habituate easily, and they are undergirded by our strengths and virtues.

MARTIN E. P. SELIGMAN, Authentic Happiness

The pursuit of happiness is enshrined in the Declaration of Independence as a right of all Americans, as well as on the self-improvement shelves of every American bookstore. Yet the scientific evidence makes it seem unlikely that you can change your level of happiness in any sustainable way. It suggests that we each have a fixed range for happiness just as we do for weight. And just as dieters almost always regain the weight they lose, sad people don't become lastingly happy, and happy people don't become lastingly sad.